Astra vs Expert Pro on paper

[PeppaPig]

Will see. How they treat Expert Pro owners…no software upgrade, no hardware upgrade… I will not trust and invest into any Devialet product.

[ada]

There are several differences inside of the ADH and PSU stages of the Astra and Expert. Again, I won't judge based on pictures but for example Expert line has an isolated enclosure for the PSU while the one on Astra is not closed or shielded in the posted pictures. I am not saying that Expert is a clear winner but both amps are measured by Devialet and the data is shared bu them. And again let's leave everything to a side what about the power figures? Dual Astra is literally half power of Expert 1000 Pro.

[Pim]

Taking a look at the comparison table in the first post, it occurs to me that the Expert / Expert Pro range never achieved Devialet's claimed specifications when independently tested and measured. (this is not a criticism of the OP, who is clear in stating that this is data from Devialet's website)

Taking a couple of numbers:

Signal-to-noise ratio: 117db vs 133db
Output impedance: 0.0057Ω (1kHz) vs 0.001Ω

I can recall seeing various measurements of the Expert where the signal to noise ratio was measured somewhere in the range of 115dB to 118dB, depending on model and which input is used. Similarly, Paul Miller's (HFN) measurements of a D170 indicated an output impedance of 0.003 ohms. Both of these figures are nearer the the quoted Astra specifications, rather than for the Expert specifications specified by Devialet. I believe that the 133dB figure originally quoted by Devialet for the Expert Pro is a genuine figure, but it is achieved by measuring in a very narrow and selective way, rather than is accordance with industry norms.

This makes me wonder if the Astra is actually very similar to the Expert Pro in terms of raw measured performance, and the difference in the numbers is simply Devialet moving to providing more honest data, measured more in line with industry standard practice.

With all that said, the output impedance of 0.0057 ohms as quoted for the Astra is a theoretically "worse" figure than the 0.003 ohms figure independently measured for a D170 Expert.

Both numbers are very, very low, so I doubt this matters much in real world listening, but I am a little surprised in seeing a theoretically worse number for the Astra, when compared to a measured number for a similar product from two generations back.

There might be a good reason for this, maybe certain compromises in the new design and the Astra is actually the better performing amp overall? Or maybe the Astra is actually a step back? I think we would need a lot more data to be clear with regard to this point, and actually listening to one might also be informative.

Listening? I prefer speculating on this forum.

[Gerronwithit]

Must take a look at the price of gold leaf as that appears to be the difference between the Expert and the Astra. To be fair, the elimination of the SD card is a miles overdue enhancement.

[thumb5]

I've been wondering how the configuration is transferred to the Astra amplifier. As far as I can see, the Astra configurator doesn't provide any means to download the configuration onto your own computer or to send it to an Astra amplifier on your network. Am I missing something (quite likely)?

ETA: I just found this: https://help.devialet.com/hc/en-us/artic...alet-Astra. It seems that the Astra phone app is mandatory, and is presumably used as an intermediary to deliver configurations to the amplifier. I wonder whether the amplifier has to have a network connection to Devialet's server to read the configuration each time it starts (I hope not) or stores the configuration in non-volatile memory of some sort.

[Vivialet]

I was never so keen to get an online configurator. I use USB or AES, no need for an internet connection. I think now you need a permanent internet connection because the amp gets his configuration online. Or maybe it keeps an offline configuration and you only need internet connectivity if you want to change it ? We'll see...

[thumb5]

In any case it looks as though the Astra is just as dependent on the existence of Devialet's on-line configurator as the current Expert series. It would have been much better (in my view, at least) for the amp to host its own configurator which could be accessed by an app and/or a web browser.

[markush]

Well there is a web server running also on the Expert, which in the past was also an option to make a firmware update. Thus it would be easy to achieve to use this web server feature to upload / sync configurations without needing an SD card anymore.

Another update: Devialet will come up with a whitepaper on the new ADH generation. There is quite some exchange going on at LinkedIn with Devialet for all having an account: https://www.linkedin.com/company/deviale...edView=all

[ada]

They didn’t even respond to my petition for 10 days, it is still an open topic. They have also wrote me that they will call me and they didn’t call me. They also wrote me about the white paper and still there is no white paper yet. They responded all of my Linkedin questions in public but they have never followed up on any of them.

[markush]

Sad to see. So obviously it’s best to communicate publicly on linked - and hopefully more users here can join over there at LinkedIn!